FB investors have shown an affinity for soon-to-expire put options

Option traders are placing short-term bets on Facebook Inc (NASDAQ:FB - 19.06) today, especially on the put side of the aisle. Around midday, the social networking concern has seen roughly 103,000 puts change hands -- representing a 66% increase to its average intraday put volume, and nearly twice the number of FB calls exchanged. However, digging deeper into the data, it appears not all of the action is of the bearish variety.

Garnering the most attention has been the November 18 put, which has seen more than 11,800 contracts cross the tape. The majority of the puts traded at the bid price, and implied volatility was last seen more than 21 percentage points higher, hinting at sell-to-open activity. By writing the puts to open, the sellers are expecting FB to remain north of $18 through the end of the week, when November-dated options expire. In this best-case scenario, the puts will remain out of the money, and the sellers can retain the entire net credit received at initiation.

However, not everyone on Wall Street is optimistic when it comes to FB. Short interest on the equity skyrocketed nearly 20% during the most recent reporting period, and now accounts for a healthy 6.7% of FB's total available float.

Technically speaking, the shares of FB are currently testing a familiar foothold in the $19 region. This area launched the security higher in mid-October, and should continue its role as a backstop. Plus, the November 19 strike is home to peak put open interest in the front-month series, with more than 78,000 contracts outstanding. Heading into Expiration Friday, this glut of puts could translate into an added layer of options-related support for FB.

Fundamentally, the company's next lockup expiration is Wednesday, Nov. 14, as restrictions on the potential sale of 804 million shares will be lifted.